Method of producing lightweight expanded slag

ABSTRACT

The present disclosure is directed to a method of forming a lightweight expanded blast furnace slag without particulate fallout and for controlling sulphur dioxide and hydrogen sulphide emissions by the injection of an oxidizing agent into the water system employed to spray down upon the pit and the slag layer being formed.

United States Patent 1191 Foxton 1451 Dec. 24, 1974 METHOD OF PRODUCING LIGHTWEIGHT OTHER PUBLICATIONS EXPANDED SLAG 0 Odor Abatment with Potass1um Permanganate Solu- [75] Inventor: S'dney Bnan Foxmn, Cockeysvllle! tion, Posselt and Reidies, l & EC Product Research and Development, Vol. 4, No. 1, Mar. 1965, pp. [73] Assignee: The Arundel Corporation,

Baltimore, Md. Primary Examiner-Robert L. Lindsay, Jr. [22] Flled' Sept 1973 Attorney, Agent, or FirmWilkinson, Mawhinney & [2]] Appl. No.: 400,921 Theibault 52 us. 01. 65/19, 75/24 1 ABSTRACT [51] Int. Cl. ..C03b19/00, C2lb 3/06 The present disclosure is directed to a method of [58] Field of Search 65/19, 20; 75/.5 C, 24 forming a lightweight expanded blast furnace slag without particulate fallout and for controlling sulphur [56] References Cited dioxide and hydrogen sulphide emissions by the injec UNITED STATES PATENTS tion of an oxidizing agent into the water system em- 3 567,413 3/1971 Miller 65/l9 Ployed Spray P011 the Pit and the Slag layer 3,738,820 6 1973 Osborn et al. 1 65 19 x bemg formed- 3,758,292 9/l973 Kuntz 75/24 3,761,243 9 1973 Kuntz 75/24 3 6 Drawmg F'gures PATENTEU 053241974 SHEET 2 BF 2,

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METHOD OF PRODUCING LIGHTWEIGHT EXPANDED SLAG An object of the present invention is to produce a lightweight expanded blast furnace slag without particulate fallout and with control over sulphur dioxide and hydrogen sulphide emissions.

A further object of the present invention is a method of forming a lightweight expanded slag by pouring molten slag into a porous bottom pit which has been wetted by umbrella sprays prior to and during introduction of the slag into the pit.

A still further object of the present invention is the control of particulate emissions, produced when the molten slag is expanded, by means of the scrubbing action of the water spray umbrella.

A still further object of the present invention is a method for forming slag employing umbrella type sprays of water into which an oxidizing agent of the group of sodium carbonate, sodium chlorine dioxide and potassium permanganate is injected to control emissions of sulphur dioxide and hydrogen sulphide produced when the molten slag comes into contact with the wet base of the pit or a wet lower layer of expanded slag.

With the foregoing and other objects in view the invention will be morefully described hereinafter and more particularly pointed out in the appended claims.

In the drawings in which like parts are denoted by reference characters throughout the several views:

FIG. 1 is a longitudinal section through a slag pit employed with the present method.

FIG. 2 is a perspective view of the pit of FIG. 1 show ing the umbrella water spray distribution system.

FIG. 3 is a hydraulic schematic of the water pumping and distribution system for the pit of FIGS. 1 and 2.

FIG. 4 is a side elevational view of the water spray header employed in the pit of FIG. 2.

FIG. 5 is a transverse section taken on the lines 55 in FIG. 4 showing the spray nozzles on the main header pipes.

FIG. 6 is a vertical section through the lines 66 of FIG. 4.

Referring now to the drawings and for the moment to FIG. 1, l0 designates a slag pit having a sloping bottom 11. At the upper or high end 13 is a rail line 14 over which ladle type rail cars 15 containing molten slag are brought for dumping. Situated in the pit 10 are support columns 16 for the water spray headers 17. The main water spray headers 17 have spray nozzles 18 spaced along their length. The nozzles may be coarse or fine. The coarse spray is used to thoroughly wet the bed and the fine sprays are turned on during or after the pour to scrub the ascending steam and carry back any particulates to the bottom of the pit. Any oxidizing agents required would be injected only during and after the pour. The preferred oxidizing agent is potassium permanganate.

The pit 10 is of a width sufficient to permit the slag to pour without obstruction which results in a thin layer of slag on the pit floor.

The spray headers 17 are supplied with water by pumps 19 having their intakes 240 in communication with a water source. Suitable valvirng 21 is provided to permit one or more of the pumps to furnish water for one or more slag pits.

The molten slag is brought to the pouring side 13 in the ladle type rail cars 15 and after the floor of the pit 10 has been thoroughly wetted by the overhead water sprays from headers 17 the molten slag is poured rap idly into the pit. The water spray system can be left run ning to form a scrubber type atmosphere. The coarse sprays would be used to thoroughly wet the bed and the fine sprays, turned on during and after the pour, would scrub the ascending steam and carry any particulates back down to the pit.

As many as four pours are expected to be made, one on top of the other, before the pit needs to be dug out. Each base layer must be completely cold and thoroughly soaked before the next pour is made.

What I claim is:

1. The method of forming a lightweight expanded slag in an open pit, comprising:

a. thoroughly wetting the pit bottom y an overhead umbrella spray system with water.

b. pouring the slag in a molten state rapidly into the pit so that by gravity flow the slag upon contacting the water is expanded,

c. wetting the slag while pouring with the umbrella spray,

d. scrubbing out during and after the pouring cycle the emissions from the expanding slag by means of said umbrella water sprays, and

e. building multiple layers of slag superposed one upon another thoroughly soaking and cooling each under layer prior to pouring a superposed layer.

2. The method of claim 1 further comprising inject ing an oxidizing agent into the water system to reduce emission of sulphur dioxide and hydrogen sulphide.

3. The method of claim 2 wherein the oxidizing agent is of the group of sodium carbonate, sodium bisulfite, sodium hydroxide, chlorine dioxide, potassium permanganate. 

1. THE METHOD OF FORMING A LIGHTWEIGHT EXPANDED SLAG IN AN OPEN PIT, COMPRISING: A. THOROUGHLY WETTING THE PIT BOTTOM Y AN OVERHEAD UMBRELLA SPRAY SYSTEM WITH WATER, B. POURING TH SLAG IN A MOLTEN STATE RAPIDLY INTO THE PIT SO THAT BY GRAVITY FLOW THE SLAG UPON CONTACTING THE WATER IS EXPANDED, C. WETTING THE SLAG WHILE POURING WITH THE UMBRELLA SPRAY, D. SCRUBBING OUT DURING AND AFTER THE POURING CYCLE THE EMISSIONS FROM THE EXPANDING SLAG BY MEANS OF SAID UMBRELLA WATER SPRAYS, AND E. BUILDING MULTIPLE LAYERS OF SLAG SUPERPOSED ONE UPON ANOTHER THOROUGHLY SOAKING AND COOLING EACH UNDER LAYER PRIOR TO POURING A SUPERPOSED LAYER.
 2. The method of claim 1 further comprising injecting an oxidizing agent into the water system to reduce emission of sulphur dioxide and hydrogen sulphide.
 3. The method of claim 2 wherein the oxidizing agent is of the group of sodium carbonate, sodium bisulfite, sodium hydroxide, chlorine dioxide, potassium permanganate. 